▎ 摘　　要

Coal gasification technology can effectively solve the problem of clean coal utilization, but the problem of volatilization of harmful metals such as arsenic in the coal gasification process cannot be underestimated. In this paper, based on DFT (density functional theory), the adsorption characteristics of As4 on the surface of different carbon-based single-atom Ti/V/Cr/Mn adsorbents (nitrogen atom-doped, single vacancy and double vacancy) were studied. The single-atom adsorbent geometry, adsorption configuration, adsorption energy, electronic structure, electron density and other data were analysed. By comparing and analysing the calculation results of sixteen adsorbents, it is found that the catalyst with the double-deficient nitrogen-doped substrate has higher stability. Through the analysis of charge transfer and density of state, it was found that the adsorption of a singleatom adsorbent catalyst to As4 is related to charge transfer and hybridization. In particular, doped nitrogen atoms can enhance the charge transfer and hybridization of the system. amongst the sixteen adsorbents, the double-vacancy nitrogen-doped Ti catalyst is a promising As4 adsorbent, which provides a reference for further research on the adsorption of toxic gases on the surface of single-atom catalysts and the design of new nonnoble metal adsorbents.